package com.demo.uitls;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.net.URL;

/**
 * Created by Administrator on 2015/3/23.
 */
public enum ImageUtil {
    INSTANCE;

    public String generateImage(byte[] b, String savePath, String filename) {
        //对字节数组字符串进行Base64解码并生成图片
        OutputStream out = null;
        try {
            //生成jpeg图片
            if (!new File(savePath).exists()) {
                new File(savePath).mkdirs();
            }
            out = new FileOutputStream(savePath + "/" + filename);
            out.write(b);
            out.flush();
            out.close();
            return savePath + "/" + filename;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        } finally {
            try {
                if (out != null) {
                    out.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public BufferedImage rotate(Image src, int angel) {
        int src_width = src.getWidth(null);
        int src_height = src.getHeight(null);
        // calculate the new image size
        Rectangle rect_des = calcRotatedSize(new Rectangle(new Dimension(
                src_width, src_height)), angel);

        BufferedImage res = null;
        res = new BufferedImage(rect_des.width, rect_des.height,
                BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = res.createGraphics();
        // transform
        g2.translate((rect_des.width - src_width) / 2,
                (rect_des.height - src_height) / 2);
        g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);

        g2.drawImage(src, null, null);
        return res;
    }

    public Rectangle calcRotatedSize(Rectangle src, int angel) {
        // if angel is greater than 90 degree, we need to do some conversion
        if (angel >= 90) {
            if (angel / 90 % 2 == 1) {
                int temp = src.height;
                src.height = src.width;
                src.width = temp;
            }
            angel = angel % 90;
        }

        double r = Math.sqrt(src.height * src.height + src.width * src.width) / 2;
        double len = 2 * Math.sin(Math.toRadians(angel) / 2) * r;
        double angel_alpha = (Math.PI - Math.toRadians(angel)) / 2;
        double angel_dalta_width = Math.atan((double) src.height / src.width);
        double angel_dalta_height = Math.atan((double) src.width / src.height);

        int len_dalta_width = (int) (len * Math.cos(Math.PI - angel_alpha
                - angel_dalta_width));
        int len_dalta_height = (int) (len * Math.cos(Math.PI - angel_alpha
                - angel_dalta_height));
        int des_width = src.width + len_dalta_width * 2;
        int des_height = src.height + len_dalta_height * 2;
        return new Rectangle(new Dimension(des_width, des_height));
    }

    public byte[] getBytes(String strUrl) {
        ByteArrayOutputStream baos = null;
        try {
            URL u = new URL(strUrl);
            BufferedImage image = ImageIO.read(u);
            //convert BufferedImage to byte array
            baos = new ByteArrayOutputStream();
            ImageIO.write(image, "jpg", baos);
            baos.flush();
            return baos.toByteArray();
        } catch (Exception e) {
        } finally {
            if (baos != null) {
                try {
                    baos.close();
                } catch (IOException e) {
                }
            }
        }
        return null;
    }
}
